diff --git a/addons/account_followup/account_followup.py b/addons/account_followup/account_followup.py
index 0e3cd0ac5f7..f05d6fc2ab5 100644
--- a/addons/account_followup/account_followup.py
+++ b/addons/account_followup/account_followup.py
@@ -273,7 +273,7 @@ class res_partner(osv.osv):
                     if date <= current_date and aml['balance'] > 0:
                         strbegin = "<TD><B>"
                         strend = "</B></TD>"
-                    followup_table +="<TR>" + strbegin + str(aml['date']) + strend + strbegin + aml['name'] + strend + strbegin + aml['ref'] + strend + strbegin + str(date) + strend + strbegin + str(aml['balance']) + strend + strbegin + block + strend + "</TR>"
+                    followup_table +="<TR>" + strbegin + str(aml['date']) + strend + strbegin + aml['name'] + strend + strbegin + (aml['ref'] or '') + strend + strbegin + str(date) + strend + strbegin + str(aml['balance']) + strend + strbegin + block + strend + "</TR>"
                 total = rml_parse.formatLang(total, dp='Account', currency_obj=currency)
                 followup_table += '''<tr> </tr>
                                 </table>